2006-11-27 04:00:00 PDT St. Louis -- Which player can the 49ers least afford to lose?

Running back Frank Gore would seem to be a consensus answer, that's why Bay Area reporters waited until Gore finished treatment on his right ankle to talk to him, long after the 49ers' 20-17 loss to St. Louis.

Gore exited late in the game with the injury and didn't return. Stadium X-rays on his lower leg were negative and the team will know more today after further examination.

Gore didn't say much about the injury after gaining 134 yards on 21 carries and wasn't immediately given a designation of doubtful, questionable or probable.

The 49ers said Gore hurt his ankle, while Gore pointed to his lower shin as the affected area. Gore, who has amassed a team record 505 rushing yards in the last three games, wanted to talk more about the game than being hobbled.

"I'm all right," he said. "It would have felt real good if we won. We're going to stay focused."

He tied a team record set by Garrison Hearst in 1998 with his third straight 100-yard rushing performance. He also tied Hearst (1998) and Roger Craig ('88) with his sixth 100-yard rushing game of the season.

In 1988, Craig set the franchise record with 1,502 yards rushing, which Hearst surpassed in '98 with 1,570 yards. With five games to go, Gore has 1,177 yards rushing.

Davis back: Rookie tight end Vernon Davis said he's all the way back from fracturing his fibula Sept. 24 against the Eagles. Davis blocked like a demon against the Rams and even had two passes thrown his way. He caught one and broke a tackle for an 11-yard gain; he dropped the other.

When asked if he'd like to catch more and block less, Davis said, "You know what I want to do. I really just want to be the complete tight end."

Battle battling hand: Arnaz Battle's fumble on a punt return was immediately turned into a touchdown by the Rams when running back Steven Jackson raced for a 36-yard score on the next play.

Battle was six days removed from surgery on his left hand when he was asked to return punts Sunday.

Battle admitted it was hard to put the ball away because of his injured hand "I guess you could say it was a small factor," he said.

Parrish down: For the second time in three games, the 49ers de-activated a healthy Tony Parrish. The team seems to be settling more on strong safety Mark Roman and Keith Lewis as its starters. Parrish and Mike Adams are playing less in each game it seems. Adams' ability to play cornerback in the nickel and dime defenses makes him too valuable to de-activate.

A first for Lawson: The 49ers drafted Manny Lawson with the 22nd pick in the first round in the hope he would provide an immediate spark as a pass-rusher. That hasn't happened (although he does have two sacks), but Lawson is contributing as a coverage linebacker.

Lawson came up with the first interception of his life on a remarkable play on the Rams' first drive of the game. From his outside linebacker position, he retreated into coverage (of Torry Holt, no less) and leaped for an interception at the sideline.

The Rams challenged the play, saying Lawson came down out of bounds, but a replay showed the rookie touched one foot in bounds and came down on his elbow. The elbow is the clincher, as it equals two feet in the NFL's curious physiological view.

Asked how he snagged the interception, Lawson said he had no idea. "I was just in position to make the play. Back in my younger days I used to play receiver, so it goes to that."

Though he hasn't developed into a pass rusher and may be too slight of build at 6-foot-5 and 240 pounds to do so, Lawson is enjoying getting on the field and contributing.

"I like my role very much," he said. "I was drafted as a pass-rusher but whatever it takes to get on the field, that's what I'll do. I just have a love for the game."

Much ado: The 49ers were hit with a rare defensive delay-of-game penalty on the Rams' winning touchdown drive when they did not get off Jackson in a timely manner. Jackson had run 4 yards to the San Francisco 9-yard line and was tackled by rookie cornerback Marcus Hudson.

Jackson struggled to get up with time running out and officials threw a flag on the 49ers for delay of game. Hudson was announced on the field as the guilty party but the official play-by-play named defensive end Bryant Young as the recipient of the flag.

After the game, Hudson said he was trying to get up but that someone was preventing him from doing so.

Either way, the Rams had no timeouts left and the penalty stopped the clock with 29 seconds to play. When the Rams scored on the next play, it left the 49ers with 27 seconds to mount a comeback. The game then ended when Alex Smith's pass was intercepted by Oshiomogho Atogwe.

Norris signs extension: The 49ers announced a three-year extension for fullback Moran Norris. Terms were not revealed. Signed to a one-year deal before the season, Norris quickly established himself as a starter.

"He's one of the reasons we're doing well in the running game," vice president of player personnel Scot McCloughan said. "He's a young guy."

Locking in Norris, an unrestricted free agent, means the team doesn't have to pursue a fullback in the free-agent market.

Bryant comments: Wide receiver Antonio Bryant refused to speak to reporters last week in the wake of his arrest in San Mateo on suspicion of driving under the influence, reckless driving and resisting arrest. He spoke briefly of the week-old incident after the game.

"Sometimes things are more than what they seem," Bryant said, obliquely. "That can be the case with high-profile people. I'm still smiling."

Asked if he intended to contest the charges against him, Bryant said, "Of course."